Supercharger for internal-combustion engines



l s. A. Moss. SUPERCHARGER FUR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED vDEC.17. 1920.

Pateted Apr. 18, 1922.

s. A. Moss. SUPERCHARGER FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED DEC.I7| 1920- 1,413,420 Patented Apr. 18, 1922.

3 SHEETS-SHEET 2.

Senf rd .77 /Vossl S. A. MOSS. SUPEBCHARGER FOR INTERNVAL COMBUSTION ENGINES.

APPLICATFON FILED DEC.17. 1920.

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UNITED STATES PATENT OFFICE.

` SANFORD A. Moss, oF LYNN, MASSACHUSETTS, ASsIGNo-E To GENERAL ELECTEIC Y COMPANY, A CORPORATION OE NEW YORK.

SUPERCHARGER FOR INTERN AICOMBUSTION ENGINES.

Specification of Letters Patent.

'Patented Apr. 18, 1922.`

Application led December 17, 1920. Serial No. 431,346.

Internal-Combustion Engines, of which'the following is a specification.

The present .invention relates to superchargers for internal combustion engines and particularly to superchargers lwhlch comprise a turbo-compressor driven '.by exhaust gases from the eng1ne. As, 1s now known, such superchargers .are employed. for supplying air to the engine at substantiallyuniform pressure irrespective ofthe surrounding atmospheric pressure, the dis- -charge side of thesupercharger compressor being connected to the engine carburetor or carburetors.

The object of my invention is to provide an improved structure and arrangement 1n an apparatus of this character and for a consideration of what I believe to be novel and my invention,- attention .is directed to the accompanying description and the claims appended thereto.

My improved structure and arrangement is particularly adapted for use in connection with aeroplanes and in the drawing I' have illustrated such application but it wlll be understood that the invention is not necessarily limited to this particular use.

In the drawing, Fig. 1 is a side elevation of an aeroplane internal combustion engine equipped with supercharger apparatus embodying my invention; Fig. 2 1s a top plan view thereof; Fig. 3 is a face view, the propeller being partly broken away; Fig. 4 is a side elevation par'tly in sectlon of a part of the structure, the figure being on a larger scale than Fig. 1, and Fig. 5 is a face view of the parts shown in Fig. 4 with the compressor casing and turbine wheel removed.

Referring to the drawing,-8 indicates the crank casing of an internal combustion envine, 9 the cylinders, and 10 the crank shaft. In the present instance, a twelve cylinder engine is illustrated there being two rows of six cylinders each arranged in V-shaped relation to each other. `The intake' manifolds 11 of the engine cylinders are located between the two rows of cylinders and are connected to carburetors 12, and the exhaust pipes 13 of the cylinders are connected to conduits 14, one on each side of the engine.

ing conduit 27a At-their forward ends conduits 14 are connected by flanged joints 15 to a nozzle box l6 and at their rear ends they are provided with suitable valves 17 which are connected by rods 18 to a suitable operating lever whereby the valves may be opened and closed at will... In nozzle box 16 are one or more nozzles 19"(Figs. 4-5) for directing exhaust gases against the buckets of a turbine wheel 20. Turbine wheel 2O has no casing. the lgases exhaustlng from it directly to atmosphere, supported in a rear bearing 22 and a forward .bearmg 22a. The compressor Casing 1sA indlcated at 23 and in itis an impeller, not shown, which receives air on opposite sides at its central portionand delivers it at its periphery to a discharge conduit 24. Air 1s supplied to the forward side of, the impeller through an opening 25 in casing 23 and to the rear side of the impeller through a conduit 26 which leads from the front of the casing` around to the rear of it. Shaft bearing 22a is located in inlet 25 and is supported by casing 23. It is preferably in the and it 1s carried by a shaft 21 form of a combined supporting and thrust i bearing which fixes the shaft against axial Inovement. A conduit 27 leads from the front of the casing 23 to the rear for discharging cooling air to a vertically extendwhich forms a housingand support for bearing 22, the air serving to cool the bearings. On crank shaft 10 is an aeroplane propeller 28 and it will be noted that opening 25 and conduits 26 and 27 face toward the propeller so as to receive air from 1t. At 27b is a baiile which takes air from the propeller and delivers it to the front side of the turbine wheel for cooling it.

.In operation when valves 17 are open the exhaust from the engine passes directly to atmosphere and no pressure is built up in nozzle box 16. When it is desired to supercharge, valves 17 are closed more or less thereby causing exhaust gases to How to nozzle box 16 and build up a pressure therein,

gases then escaping through the nozzle or nozzles 19 against the buckets on turbine wheel 20. This drives the turbo-compressor, the impeller of the compressor delivering air to discharge conduit'24. The speed of the turbo-compressor and hence the pressure of the air discharged can be controlled by adjusting valves 17 as is now. understood,

The gases exhaust from the engine at a high temperature which'means that the nozzle box, turbine wheel and parts associated therewith become very hot during operation, thereby causing considerable expansion and contraction of the parts, also the air dischar ed from the compressor ma be quite hot ue to being compressed. present invention relates more particular y to the structure and arrangement for mounting the supercharger on the engine so it may expand and contract without getting out of ali nment or becoming distorted and proviiing for the cooling of the supercha'rfged air after it leaves the compressor and be ore it is delivered to the engine.

According to my invention, the supercharger comprising the turbo-compressor, nozzle box, rear bearing and forward bearin are built as a unitary, rigid structure and this structure is then carr1ed by a bracket supported on the engine, the bracket being adapted to permit the rigid su rchar r structure to move axially as a w ole.4 he carburetors are arranged above the engine cylinders and are connected to the discharge side of the compressor by a number of pipes which have a certain amount of flexibility to permit limited axial movement of the supercharger structure. These pipes also serve as a cooler for the supercharged air being arranged in the aeroplane propeller air stream so that air discharged from the aeroplane propeller passes over them. I also so arrange the structure that the com ressor and turbine wheel may be remove from the engine without disturbing the nozzle box or its connections with exhaust conduits 14. This is an important consideration as the joints 15 have to be made to stay tight under most severe operating conditions and hence it is very desirable not to disturb them after the have been sealed up.

geferring to the particular embodiment of my invention illustrated in the drawing, the

supporting bracket comprises two spaced` vertical arms 30 connected adjacent their lower ends b a transverse rib 31. The lower ends o arms 30 have inturned portions 32 which rest on and are bolted to the nose of the engine as indicated at 33. The upper ends of arms 30 are provided with bosses 34 which are bolted by bolts 34a directly to lugs 35 which depend from the nozzle box. At its top the' nozzle box is connected to the compressor casing by a flat plate 36. the plate being preferably formed `integral with or welded to the nozzle box and detachably connected to the compressor casing as by a bolt or bolts 37. At its two sides the nozzle box is also supported by exhaust conduits 14 to which it is bolted at the flanged connections 15. The rear bearing 22 is supported by suitable webs 38 in the enlarged upper portion of conduit 27a. The forwardly facing opening of conduit ycarried by t 27 joins conduit 27 in the vertical plane marked B in Fig. 4. The outline of this openin is shown 1n Fig. 5 at C. At the two sides 0% conduit 27a are marginal flanges 39 which are bolted directly to pads 40 on lthe rear of the compressor casing b bolts 41. Flanges, 39 are fastened to brac ets 30 by bolts 42. By this arrangement the rear bearing is directly fastened to and forms a rigid structure withv the compressor casing and both the compressor casing and bearing are e supporting bracket which comprises arms 31. The carburetors 12 are provided with an air supply header 44 and this header is connected to discharge conduit 24 of compressor 23 by a number of curved tubes 45.

It will thus be seen that the su rcharger as a whole can move slightly axialllye, the su porting bracket and tubes 45 being sugciently flexible to rmit of this, and since it moves as a unit t e bearing alignment will not be disturbed. Such movement may be caused for example, by the expansion and contraction of exhaust conduits 14.

As will be clear, the arrangement is such that the nozzle box or any of the other parts containin hot gases can warp or distort without c anging the line-up of the turbine wheel in its bearings. The bearings are all mounted on a structure which remains more or less cool and which forms a single unit independent of the nozzle box structure. It will be noted that the nozzle plate in which nozzles 19 are formed is supported by bracket arms 30 so such nozzles are supported by the same flexible support which also supports the structure carrying the compressor casing, both shaft bearings being likewise attached directly to this structure. The structure carrying the compressor casing is comparatively cool, hence no matter how much the parts subjected to red hot gases expand and warp, the turbine wheel will always remain closel adjacent the nozzle plate through which t e hot gases pass to the turbine wheel.

Since bearing 22 is in the form of a thrust bearing, when expansion takes place there will be no relative movement between the impeller wheel and its casing and hence there is no tendency for the impeller to take a position where it might strike the casing. If there is relative expansion between the structure carried by the flexible supporting bracket and the shaft, it will cause the clearance between theturbine wheel and the nozzle plate to vary. However, the shaft and casing structure are comparatively cool so this differential expansion is negligible compared with the clearance between the turbine wheel and the nozzle plate. As a result striking or rubbing of either the turbine wheel or compressor impeller with adjacent stationary parts is avoided.

. casing wit-hout disturbing' the rear bearing If it is desired to remove the turbo-compressor for replacement, repair or other reasons. bolts 37 and 42 are removed when the unit comprising compressor, turbine wheel and rear bea-ring can be lifted from the engine as a whole. This'does not disturb the nozzle box or its connections with conduits 14, and avoids the breaking of the sealed connections 15.

If it is desired to remove the compressor then instead of removing bolts 42, bolts 41 may be removed. This permits the compressor casing and turbine Wheel to be removed but leaves the rear bearing bolted to bracket arms 30.

The air delivered by compressor 23 passes through tubes 45 to carburetor header 44 and while passing through the tubes is cooled by the outside air passing over the outer surface ofthe tubes.- Since tubes 45 lie directlyin the air stream of the propeller 28 a lar e volume of air passes over and around t em thereby most efiiciently cooling the supercharged air.

In accordance with the provisions of-the Patent Statutes, I have described the prin- 'ciple of operation of my invention, together with the .apparatus which I now consider to represent the best embodiment thereof, butl I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

lVhat I claim as new and desire to secure by Letters Patent of the United States, is

1. In combination, an internal combustion engine, a supercharger, a conduit connected to the supercharger and to the engine which is subjected to temperature changes which cause 1t to expand and contract, and means for yieldingly supporting the supercharger on the engine.

2. In combination, an internal combustion engine having an exhaust conduit, a supercharger having a nozzle box fastened to said conduit, and yielding means for supporting the supercharger.

3. In combination, an internal combustion engine having an exhaust conduit, a supercharger having a nozzle box fastened to said conduit. and an axially yieldable bracket for supporting the supercharger.

4. In combination, an internal combustion engine having an exhaust conduit, a supercharger comprising a'compressor casing and a nozzle box, said nozzle box being fastened to the exhaust conduit, and a yieldable bracket for supporting the super-charger, said nozzle box and compressor casing being fastened to the bracket by separate means.

5. In combination, an internal combustion engine having an exhaust conduit, a supercharger comprising a turbo-compressor and a nozzle box, the latter being fastened to said exhaust conduit, yielding means for supporting the supercharger on the engine, and yielding conduit means connecting the discharge side of the compressor to the engine.

6. In combination, an internal combustion engine having anexhaust conduit, a supercharger comprising a turbo-compressor and a nozzle box, the latter being fastened to said exhaust conduit, an axially v yieldable bracket for supporting the supercharger, and conduit means connecting the discharge side of the compressor tothe englne. 7 The combination with an aeroplane en` gine having a propeller on its crank shaft, and an exhaust conduit, of a-supercharger comprising a turbo-compressor and a nozzle box, the latter being fastened to said exf haust conduit, yielding means for supporting the supercharger on the engine, and yielding conduit means located in the air stream of the propeller and connecting the l discharge side of the compressor to the enf,k i glne.

8. The combination with an aeroplane en. gine having a propeller on its crank shaft, of a supercharger for the engine, means for supporting the supercharger, and conduit means comprising a plurality of pipes for conveying supercharged air from'the supercharger Vto the engine, said conduity means l being located in the air stream of the propeller.

9. The combination With an aeroplane engine having ak propeller on its crank shaft, of a supercharger for the engine, means for supporting the supercharger, and a plurality of pipes located in the air stream of the propeller for conveying supercharged ail` from the supercharger to the engine.

10. The. combination with an aeroplane engine having a propeller on its crank shaft and an exhaust conduit, and a supercharger comprising a turbo-compressor adapted to be operated by exhaust gases from the engine and a nozzle box connected to said exhaust conduit, of an axially yieldable supporting bracket, and means connecting the turbo-compressor and nozzle box to said bracket.

1l. The combination with an aeroplane engine having a propeller on its crankshaft and an exhaust conduit, a supercharger comprising a turbo-compressor adapted to be operated by exhaust gases -from the 'engine and a nozzle box connected to said exhaust conduit, of an axially yieldable supporting bracket, separate means connecting the compressor casing and the nozzle. box to said bracket, and detachable means connecting the nozzle box to the compressor casing.

12. The combination with an aeroplane engine having a propeller on its crank shaft and an exhaust conduit, a supercharger com- 13@ prising a turbo-compressor adapted to be yeldable conduit means located in the prooperated by exhaust gases from the engine peller air stream connecting the discharge 10 and a nozzle box connected to said exhaust side of the compressor to the engine.

conduit, of an axially yieldable supporting In witness whereof, I have hereunto set bracket, separate means connecting the commy hand this thirteenth day of December, pressor casing and the nozzle box to said 1920.

bracket, detachable means connecting the nozzle box to the compressor casing and SANFORD A. MOSS. 

